Snap knife with improved safety and usability

Abstract

A utility knife using segmented, snap-off blades, or snap knife, incorporating an improved means for snapping off the dull segments. A two part handle is pivotally interconnected so that when closed, a standard handle is formed. When open, the two parts of the handle are aligned opposite each other. The blade, contained in one part can be advanced to enter a slot in the other part. With the segment line of the blade aligned in the gap between the two parts, the blade can be snapped by closing the handles. The snapped segment is preferably retained within the handle for later disposal.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application claims the benefit of U.S. Provisional Application No. 60 / 501,204 filed Sep. 8, 2003 and of provisional application 60 / 579,865 filed Jun. 15, 2004.STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT [0002] Not Applicable BACKGROUND OF THE INVENTION [0003] 1. Field of the invention [0004] The present invention relates to the field of utility knives and specifically to such knives as use a segmented blade from which dull segmented can be broken off. [0005] 2. Background Information [0006] Utility knives in their many forms are well known in the art. They are used by a wide variety of trades people, and others, on a daily basis. Utilizing disposable blades, they offer an easy method of having a sharp knife readily available without the need to stop for sharpening. [0007]“Snap knives”, or utility knives which use a segmented blade from which segments are snapped off, and disposed of, as they become dull are also...

AI Technical Summary

Benefits of technology

[0021] The advantages of such an apparatus are increased safety and usability. A dull segments can be quickly snapped off the blade without the user ever being required to touch the blade or to move the knife any significant distance from its working position. The process merely involves retracting the blade, opening the handles, advancing the blade into the second slot, and closing the handles. That done, the blade has been snapped and work can process.

Problems solved by technology

Snap knives also suffer disadvantages relative to standard utility knives.

While considered dull by the user, these segments still retain a sharp edge and point.

The typical methods of snapping off a dull segment pose a risk to the user.

This risk comes from the need to handle the bade and removed segment, both of which are sharp, and from the tendency for the snapped segment to fly away as a result of the snapping operation.

As is readily apparent, when the blade snaps, it releases a significant amount of energy which typically results in the freed segment being projected away at high speed.

Clearly, a flying blade segment with a sharpened edge poses a risk to both the user and those in the vicinity.

There is also significant risk of damage to the surface used for the snapping operation, both from the end of the blade and from the handle of the knife after the blade snaps.

These reduce the likelihood of the segment flying free, but often leave the cutting edge of the segment exposed to the user's fingers during the operation.

As such they pose a hazard if not disposed of properly, Unfortunately it is common practice to leave them littering the floor of the work place, intentionally or unintentionally.

Because of their small size, flat shape, and tendency to be projected outward, blade segments become lost easily.

Even if found, they are hazardous to pick up due to their sharp edge and tip.

The result is that even the best intentioned user usually leaves a few segments behind.

While effective, these devices can be inconvenient to use.

In others, such working in physically restrictive area, such as the crawl space under a house, or on top of a ladder, this burden may be sufficiently excessive to cause the user to forego the use of the container return to simpler methods and let the segment fall.

A further problem with the slotted container approach is that the blade must be inserted into the slot.

Not a significant problem if working at a bench in a well lighted shop, but a major challenge in low light situations, cramped quarters (especially where the container may not be in line of sight), or where the user is unstable or moving.

Again, these difficulties may cause the user to bypass the safe method and revert to snapping and discarding segments using whatever method is available.

Images